The invention concerns a process for depositing a coat of paint on wood-cement boards manufactured by pouring a strewable mixture of fibers and binder on pressing plates and then pressing into stacks, the pressing being followed by depositing paint on the board surface.
The board can be either without a coat of paint or else be provided with integral dyeing from an additive to the strewable mixture.
A drawback is incurred in this procedure in that especially where such boards are used externally, the coat of paint deposited after pressing will flake off again in the course of time because of inadequate adhesion to the wood fibers of the wood-cement board.
As regards the integrally dyed boards, a coloring will remain even after the additionally deposited layer of paint has flaked off, but there is a drawback in this case that following the flaking-off of the coat of paint, the cement will bloom because of its lime, and the boards become unsightly.
These drawbacks become especially perceptible in extreme weather and in particular with respect to roof-covering boards.